'\" et
.TH SETPGRP "3P" 2017 "IEEE/The Open Group" "POSIX Programmer's Manual"
.\"
.SH PROLOG
This manual page is part of the POSIX Programmer's Manual.
The Linux implementation of this interface may differ (consult
the corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
.\"
.SH NAME
setpgrp
\(em set the process group ID
.SH SYNOPSIS
.LP
.nf
#include <unistd.h>
.P
pid_t setpgrp(void);
.fi
.SH DESCRIPTION
If the calling process is not already a session leader,
\fIsetpgrp\fR()
sets the process group ID of the calling process to the process ID of
the calling process. If
\fIsetpgrp\fR()
creates a new session, then the new session has no controlling
terminal.
.P
The
\fIsetpgrp\fR()
function has no effect when the calling process is a session leader.
.SH "RETURN VALUE"
Upon completion,
\fIsetpgrp\fR()
shall return the process group ID.
.SH ERRORS
No errors are defined.
.LP
.IR "The following sections are informative."
.SH EXAMPLES
None.
.SH "APPLICATION USAGE"
It is unspecified whether this function behaves as
.IR setpgid (0,0)
or
\fIsetsid\fR()
unless the process is already a session leader. Therefore, applications
are encouraged to use
\fIsetpgid\fR()
or
\fIsetsid\fR()
as appropriate.
.SH RATIONALE
None.
.SH "FUTURE DIRECTIONS"
The
\fIsetpgrp\fR()
function may be removed in a future version.
.SH "SEE ALSO"
.IR "\fIexec\fR\^",
.IR "\fIfork\fR\^(\|)",
.IR "\fIgetpid\fR\^(\|)",
.IR "\fIgetsid\fR\^(\|)",
.IR "\fIkill\fR\^(\|)",
.IR "\fIsetpgid\fR\^(\|)",
.IR "\fIsetsid\fR\^(\|)"
.P
The Base Definitions volume of POSIX.1\(hy2017,
.IR "\fB<unistd.h>\fP"
.\"
.SH COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1-2017, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, 2018 Edition,
Copyright (C) 2018 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group.
In the event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html .
.PP
Any typographical or formatting errors that appear
in this page are most likely
to have been introduced during the conversion of the source files to
man page format. To report such errors, see
https://www.kernel.org/doc/man-pages/reporting_bugs.html .
